Holy Smoke

If it's broken or just needs tweaked

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Rocket Man
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Holy Smoke

Postby Rocket Man » Sat Nov 30, 2013 6:24 pm

My 650 has just over 7000 miles on it and after being resurrected I have still another issue. I may be loosening up the rings with Marvel Mystery Oil, but do get white/blueish smoke at idle from some cylinders. My compression is at 80 psi in all cylinders, which sounds low. The stem seals should not be worn at 7000 miles, but rings could be sticking. What should I do? It is also possible that the o-rings in the top of the barrels is leaking to the inside. Not ready to tear into the top end yet. :roll:

cb650
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Re: Holy Smoke

Postby cb650 » Sun Dec 01, 2013 12:25 am

Seals might not have worn out but over time they will become brittle. Especially on a bike that has sit. Comp is low but if its running ride it some and get a idea what else it needs.
Did you clean the tank out?!?!?!?!

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Volker_P
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Re: Holy Smoke

Postby Volker_P » Wed Dec 04, 2013 5:11 am

How many miles since it runs again? Did it ever get really warm during a longer, extended ride since then?

If due to rings and if you already see something at idle, it should smoke like hell above 5000rpm.

How much oil consumption?
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Rocket Man
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Re: Holy Smoke

Postby Rocket Man » Tue Dec 17, 2013 11:53 pm

How many miles since it runs again? Did it ever get really warm during a longer, extended ride since then? I have put a few hundred miles on it since it was mothballed for 10 years or so. I have not taken it on a really long ride, 30 miles or so.

If due to rings and if you already see something at idle, it should smoke like hell above 5000rpm. Not smoking at higer RPMs, or at least not noticeable. Thinking about re-torquing the head for grins. Probably has never been done.

How much oil consumption? Not too bad, trying to get a handle on it but smoke is smoke. How much can I tolerate is the question. O-ring or valve guide seal seems the most likely culprit to me so far.

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Volker_P
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Re: Holy Smoke

Postby Volker_P » Thu Jan 02, 2014 4:25 am

If you remove the header pipes, you may see if the exhaust valve stems are oily. Mine were before this action.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum


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